Removing yaw waggle ?

[sumone]

I like to create my own designs and some times my 4 channel planes (aileron , elevator , rudder throttle ) have a slight bit of side to side tail waggle or i suppose you might call it yaw waggle.
also i find with my flying wing designs if i use winglets i get the waggle if its a bit windy but with 2 vert. stabilizers i don't.

Anyone know what might be causing this and mabey have a solution to correct it.

Cheers.

 

[Hai-Lee]

I like to create my own designs and some times my 4 channel planes (aileron , elevator , rudder throttle ) have a slight bit of side to side tail waggle or i suppose you might call it yaw waggle.
also i find with my flying wing designs if i use winglets i get the waggle if its a bit windy but with 2 vert. stabilizers i don't.

Anyone know what might be causing this and mabey have a solution to correct it.

Cheers.

The degree of "Waggle" is determined by a number of factors such as the weight of the plane, the mass distribution, the distance from the vertical fin to the CG, the size of the vertical fin, the flying speed, and even the throttle setting if the fin is in the propeller wash.

The shorter the distance between the fin and the CG the less "Waggle"
The more concentrated the mass of the plane, (around the CG), the Greater the "Waggle"
A heavier plane will definitely "Waggle" less unless it is a large design with a large vertical fin!

Have fun!

 

[TEAJR66]

This is an excellent resource for doing the math that goes into figuring tail volumes and moments.

https://www.flitetest.com/articles/easy-aircraft-design

Keep in mind the forces affecting the plane.

https://www.grc.nasa.gov/www/k-12/airplane/drag1.html

For the flying wing designs, I would recommend experimentation. Explore tapered chord vs a more constant chord. I.E. try a Versa Wing and a Synapse (

). Also experiment with winglet size, position, and angle.

Good luck with your design endeavors. Share pics and vids whenever possible.

 

[quimney]

I'm not sure what kind of design you are looking at. I designed a conventional 4 channel plane that exhibited dutch roll. I increased the tail size about 10% and it cleared up completely. I'm not sure from your description if this applies to your plane but it might be something to look at.

 

[sumone]

Decreased the Vert. Stab. size and it fixed the issue.